Vegetable glue and process of making the same



UNITED STATES PATENT OFFICE.

FREDERIC S. WILLIAMS, OF CHICAGO, ILLINOIS, AND JAMES G. B. PERKINS ANDJULIUS B. B. STRYKER, OF LANSDALE, PENNSYLVANIA, ASSIGNORS TO PER- KINSGLUE COMPANY, A CORPORATION OF PENNSYLVANIA.

No Drawing.

To all whom it may concern:

Be it known that we, Fnnnnnro S. WIL- LIAMS, a citizen of the UnitedStates, and a resident of Chicago, county of Cook, in the State ofIllinois, JAMES B. PERKINS, a citizen of the United States, and aresident of Lansdale, county of Montgomery, State of Pennsylvania, andJULIUS B. B. STRYKER, a citizen of the United States, and a resident ofLansdale, county of Montgomery, State of Pennsylvania, have inventedcertain new and useful Improvements in Vegetable'Glue and Processes ofMaking the Same, of which the following is a specification.

Our invention relates to improvements in vegetable glue and process ofmaking the same. More particularly, the invention relates to asubstantially neutral vegetable glue, having substantially the qualitiesof animal glue, for gluing up veneers, and process of making the same.

In U. S. Reissue Letters Patent No. 13436, dated July 2, 1912, and in U.S. Letters Patent Nos. 1,020,656, 1,078,691, 1,078,692 and 1,200,488,there are disclosed methods of making vegetable glue by dissolving astarchy carbohydrate with caustic alkali,

such as caustic soda, the resulting glue be-' ing markedly alkaline.Even if the percentage of caustic alkali be reduced to about line sothat when applied to very thin veneers of certain woods, it will cause adiscoloration of the wood veneer, which discoloration may appear on theopposite side of the wood layer from that on which the glue is applied.In many cases this discoloration is not a serious disadvantage, and withthe thicker veneers it is not objectionable or does not appear at all.With certain kinds of wood and in certain cases, especially Where verythin layers of wood are being glued together, this discoloration orstaming may be a detriment, which 1t is desirable to avoid.

The main object of the present invention is to provide a vegetable gluehaving substantially the properties of the glue described in said U. S.Letters Patent, but which is so made or treated that this dis-Specification of Letters Patent. ,Patented May 17, 1921,

Application filed October 9, 1917. Serial No. 195,544.

coloration or staining isavoided. It is also desirable to provide avegetable glue for this purpose which is somewhat more fluid than thathitherto in use. Further objects, features and advantages will moreclearly appear from the detailed description given below.

In producing the new glue, we take a suitable starchy carbohydrate,preferably the glue base resulting from the preliminary treatmentdescribedin either of said U. S. Letters Patent. However, certainstarches appear on the market which require no preliminary treatment,and these may be used, if desired. Vhether such starch is suitable maybe easily determined by testing the. same. We preferably use cassavastarch or tapioca flour.

To make the glue, a suitable starchy carbohydrate is preferablydissolved with about 3 parts or less by weight of water and about 3% byweight of caustic soda. the caustic soda being added in the form of a33% solution. The starch is first thoroughly mixed with the water andthen the caustic soda solution added gradually with continual stirring,until the batch is transformed from a mixture of suspended starch inwater to a homogeneous colloidal solution of starch, alkali and water,having substantially the properties of good animal glue for gluing uphigh grade wood veneers, as described in said Letters Patent. Theresulting glue, although thick and viscous, is capable of flowingthrough pipes 2 inches in diameter, is capable of being spread by glueapplying machinery and has substantially the adhesive qualities ofanimal glue for this class of work.

To prevent this glue from discoloring and staining the wood, as abovedescribed, we add thereto a neutralizing agent after the alkali hasacted upon the starch, so as to make the glue substantially neutral. Forthis purpose, we may add oxalic acid in the form of a fine powder or inthe form of a solution, suflicient of the oxalic acid being added tomake the glue substantially neutral. We prefer to add the acid until theglue has a faint acid reaction. Other neutralizing agents, such asacetic acid and salicylic acid may be used, as well as certain acidreacting for the making of a high grade glue for use in gluing upveneers, the h0m0geneouscharacter of the colloid must as far as possiblebe retained, whereas in the textile and other arts granulated,flocculated or segregated products, lacking in the high tensile strengththat results from the perfect homogeneity of the colloid, may be used.We prefer, therefore, to use the organic acids forming less dissociableor ionizable salts after reaction witli the caustic soda to beneutralized, and to add them carefully so as to minimize theelectrolytic fiocculating action upon the starchy carbohydrate.

While the acids may be added in the form of solutions, we prefer to addthe neutralizing agent in dry form and also to mix with it about anequal weight of silicious material, such as finely ground feldspar,quartz or silica. Instead of caustic soda for dissolving the starch,other alkaline compounds may be used, such as caustic potash.Preferably. less than 12% by weight of caustic alkali is used indissolving the starch.

While we prefer to heat the mixture during the dissolving of the starch,the temerature being carefully kept considerably elow 175 F., yet ifmore than 3% of caustic alkali is used, as for example, 8%, the solutionof the starch may be brought about without heating the batch. Bycarefully regulating the heat, even less than 3% of caustic alkali maybe used. If heat is used, it should be carefully regulated to pre ventlocal overcooking of the starch or overcooking by a long continuedrelatively high temperature. This may be done as described in U. S.Patent 1,251,275 issued Dec. 25, 1917.

The neutralizing agent, when added in dry form, should be very finelyground, and is preferably added to the glue when the same has cooled offand after the starch has been thoroughly dissolved by the alkali.

If, on standing a considerable time, the glue thickens up, so that it istoo viscous and does not flow readily enough, it may-in most cases bebrought back to proper condition by heating it up to 130-l40 F. andthoroughly stirring it.

While the amount of water used in the process may be varied somewhat, wepreferably use 2% to 2} parts of water by weight, based on the drystarch base used. The neutralizing agent when added should be thoroughlystirred in, so that all parts of the batch will have an opportunity tobe acted upon thereby. The addition of the silicious filler seems toincrease the adhesive strength of the glue, or prevent the adhesivestrength of the glue from being materially decreased. It is, of course,not necessary thatthe neutral glue be used for joining layers of wood,as it may be found advantageous for joining fabric to wood and forjoining other articles.

While we have described our improvements in great detail and have givencertain examples, we do not desire to be limited thereto, since manychanges may be made and other reagents used, as will be understood bythose skilled in the art. It is desired to cover all modificationscoming within the language of the appended claims.

What we claim as new and desire to .secure by Letters Patent is:

1. The improved vegetable glue comprising a starchy carbohydrate insolution in about 3 parts or less by weight of water and containing asalt of an alkali metal and asilicious filler and being substantiallyneutral and having substantially the properties of animal glue forgluing up veneers.

2. The improved vegetable glue containing a starchy carbohydrate incolloidal solution with water, having substantially the adhesive,spreading and flowing qualities of animal glue for gluingup veneers andbeing substantially neutral.

3. The improved vegetable glue comprising a starchy carbohydratedissolved with caustic alkali and about 3 parts or less by weight ofwater and being substantiall neutral and havin substantially thequalities of animal gliie for gluing up high grade veneers.

4. The improved vegetable glue comprising a starchy carbohydrate insolution in about 3 parts or less by weight of water and containing asalt of an organic acid and an alkali metal, and being substantiallyneutral and having substantially the properties of animal glue forgluing up veneers.

5. The process of making vegetable glue which consists in dissolving astarchy carbohydrate with caustic alkali and' about 3 parts or less byweight of water and heat below 175 F., the carbohydrate being such thatthe resulting alkaline solution has substantially the properties ofanimal glue for gluing up high grade veneers, and then substantiallyneutralizing the glue without materially decreasing its strength orspreadabilit 6. The process of making vegetable glue which consists indissolving a starchy carbohydrate with an'alkaline compound and water toform a viscous alkaline glue, the carbohydrate being such that theresulting glue has substantially the properties of animal glue forgluing up veneers and adding an organic acid to substantially neutralizethe glue without materially decreasing its stren th or spreadability.

7. he process of making vegetable glue which consists in dissolving astarchy carbohydrate with caustic alkali and about 3 parts or less byweight of water and heat below 175 F., the carbohydrate being such thatthe resulting solution has substantially the properties of animal gluefor gluing up high grade veneers, and then adding a neutralizing agentto substantially neutralize the glue, and a silicious filler.

8. The process of making vegetable glue which consists in dissolving astarchy carbohydrate with caustic alkali and about 3 parts or less byweight of water and heat below 175 F., the carbohydrate being such thatthe resulting alkaline solution has substantially the properties ofanimal glue for gluing up high grade veneers, and then adding aneutralizing agent to substantially neutralize the glue when it hascooled off without materially decreasing its strength or spreadability.

9. The process of making vegetable glue which consists in dissolving astarchy car-- bohydrate with about 3 parts or less by weight of waterand an alkaline compound, the carbohydrate being such that the resultingalkaline solution has substantially the properties of animal glue forgluing up veneers and substantially neutralizing the glue withoutmaterially decreasing its strength orspreadability.

10. The process of making vegetable glue which consists in dissolving astarchy carbohydrate with about 3 parts or less by weight of water andan alkaline compound, the carbohydrate bein such that the resultingsolution has suiistantially the properties of animal glue for gluing upveneers,

and then adding a neutralizing agent to substantially neutralize theglue, and a silicious filler.

11. The process of making vegetable glue which consists in dissolving astarchy carbohydrate with Water and an alkaline compound, thecarbohydrate being such that the resulting alkaline solution hassubstantially the properties of animal glue for gluing up veneers andglue Without materially decreasing its strength or spreadability.

12. The process of making vegetable glue which consists in dissolving astarchy carbohydrate with water and an alkaline compound, thecarbohydrate being such that the resulting alkaline solution is a thickviscous mass capable of flowing through pipes two inches in diameter andof being spread by glue applying machinery and of adhesively securinglayers of wood together, and adding a neutralizing agent thereto tosubstantially neutralize the glue without materially decreasing itsstrength or spreadability for Wood veneering.

In testimony whereof we have signed our names to this specification.

FREDERIC S. WILLIAMS. JAMES G. B. PERKINS. JULIUS B. B. STRYKER.

\Vitnesses as to Frederic S. lVilliams:

MARGUERITE M. MULLANY, HARRY J. RosENFELo. lVitnesses as to James G. B.Perkins and Julius B. B. Stryker:

G. H. LOVE, 1. E. Moore.

substantially neutralizing the l

